Before I realised that "flying" a cable out to the car was quicker and easier (see: https://www.speakev.com/threads/home-chargepoint-with-cable-reel.143803/post-2716303), I spent some time looking into how to get a cable across the footpath with minimum of risk to pedestrians.ebay search on Industrial Cable Protector then try the links at bottom gets me sites like this:
and take your pick! Screw fix have a relatively lightweight protector, but looks like you'ld be poking the cable through the rubber seal every time you use it; the one shown above looks nicer, I suspect you just open the lid & drop the cable in, or something simple like that.
One interesting nugget: there's a generally-accepted legal threshold which seems to be well known to ambulance-chasers and claims firms, and which is used in cases of potential negligence relating to trip hazards (e.g. for claims against a local authority for uneven paving). The threshold is 25mm i.e. the trip hazard must be shown to protrude or indent by 25mm for a claim to succeed e.g. https://direct2compensation.co.uk/help-articles/how-do-i-know-if-i-have-a-valid-claim-for-tripping-accident-compensation
I am not a lawyer, but since this was pretty much the only concrete data I could find on trip hazard sizes, I thought I'd see if I could find a cable protector slim enough to fall below the threshold. Short story: there aren't many that have both the necessary cable capacity and a sub-25mm profile. In fact, I only managed to find one such profile - Vulcascot Type A - and it's eye-watering expensive, and somewhat hard to get hold of. I got it here in the end: https://www.kingfisherdirect.co.uk/vulcascot-type-a-industrial-cable-protector.
It's good stuff though, and the peace of mind knowing I've done the best I can to minimize the hazard is worth something to me (I marked it up with yellow/black tape and used it with some "Caution, trip hazard" signs, like the ones back up the thread).
BTW, if anyone wants a bit of Vulcascot Type A, PM me - I've got a 3m offcut and I'm a reasonable man